Question

我正在尝试将数据从页面发送到flutter项目中的另一个页面，尝试了在另一个问题中发现的所有方法，但都失败了，这是我的代码：

第一页：

Navigator.pushNamed(context, '/line_details', arguments: {'line':line,});

第二页：

class _LineDetailsState extends State<LineDetails> {

  Map data = {};

  @override
  Widget build(BuildContext context) {
    data  = ModalRoute.of(context).settings.arguments;
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.deepPurple,
        title: Text("$data"),
      ),
    );
  }
}

注释：line是创建的自定义对象。

错误：始终会返回null，即使尝试以{"test": "test string"}的形式发送单个字符串，它也会返回null

Answer 1

您的示例运行正常

MaterialApp中的路线

routes: { "/line_details": (context) => LineDetails(), },

按下FlatButton：

onPressed: () => Navigator.pushNamed(context, '/line_details', arguments: {'line':'test',}),

LineDetails类

class LineDetails extends StatefulWidget {

  @override
  _LineDetailsState createState() => _LineDetailsState();
}

class _LineDetailsState extends State<LineDetails> {

  Map data = {};

  @override
  Widget build(BuildContext context) {
    data  = ModalRoute.of(context).settings.arguments;

    print(data);
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.deepPurple,
        title: Text("$data"),
      ),
    );
  }

}

与GestureDetector一起工作

new GestureDetector(
            onTap: () => Navigator.pushNamed(context, '/line_details', arguments: {'line':'test',}),
            child: new Container(child: new Text("GestureDetector"),),
          ),

Answer 2

尝试一下：

Navigator.push(
    context,
    LineDetailsState(
        builder: (context) => LineDetailsState(
              line: line
            )))

和

class LineDetailsState extends StatefulWidget {
  LineDetailsState(this.line);

  Line line;

  @override
  _LineDetailsState createState() => _LineDetailsState();
}

class _LineDetailsState extends State<LineDetails> {

  Map data = {};

  @override
  Widget build(BuildContext context) {
    data  = ModalRoute.of(context).settings.arguments;
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.deepPurple,
        title: Text("$data"),
      ),
    );
  }
}

用“自定义对象”的名称代替“行”

Answer 3

您的示例看起来很正确，您可以尝试的另一件事是键入您的参数像下面这样帮助飞镖掉毛。请注意，这与您获取空值无关

    class LineDetails extends StatefulWidget {

  @override
  _LineDetailsState createState() => _LineDetailsState();
}

class _LineDetailsState extends State<LineDetails> {

  Map data = {};

  @override
  Widget build(BuildContext context) {
    data  = ModalRoute.of(context).settings.arguments as Map<String,object>;

    print(data);
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.deepPurple,
        title: Text("$data"),
      ),
    );
  }

}

如何在颤抖的视图之间发送和接收参数

3 个答案: